The present invention relates generally to the cutting of glass and, more particularly, to the breaking out of glass sheets of predetermined patterns from oversized glass blanks.
In a glass production operation, oversized glass sheets or blanks are cut or trimmed to final size for use in specific applications, such as for glazing closures in automobiles and the like. In recent years, apparatus has been developed to automtically break out the desired prescored glass pattern from a glass blank. Generally, such apparatus includes a flat supporting surface for supporting a rigid break out template having an outside configuration approximating the prescored pattern inscribed on the glass blank to be trimmed. The blank is supported on a conveyor belt sandwiched between the glass blank and the template. The apparatus includes means for accurately positioning the blank on the conveyor and vertically aligning the same relative to the underlying template located beneath the conveyor belt.
A suitable pressure applying means, such as a resilient roller for example, mounted above the glass blank, is brought into pressure contact therewith to crack off the marginal strip portions of the blank along the score line about the peripheral edges of the template and break out the desired glass pattern. The finished broken out glass piece is then removed and the conveyor belt is actuated to remove the relatively narrow severed strip portions trimmed off the finished piece.
A problem encountered with these prior known break out devices is the difficulty in consistently obtaining a uniform clean break out of the prescored glass pattern. Very often the break out yields chipped, flared or ragged edges, especially at or adjacent the corners of the finished pieces, resulting in considerable marginal waste and decreased yields.